The new Varia RearVue 820 doesn’t just tell you a car is coming. It tells you how big it is, how scary it is, and whether it’s about to ruin your KOM attempt.
Garmin has launched its latest Varia rearview radar, the horrifically named Varia RearVue 820, and it is a significant leap forward for the device that single-handedly stopped your clubmates from looking over their left shoulders every 15 seconds.
At $299.99, it’s pricier than its RTL515 predecessor. But what isn’t more expensive in 2026? Besides misery, and we ride our bikes to avoid that, or at least give it a sweatier face.
It Knows How Big the Truck Is
The headline feature here is Advanced Vehicle Tracking. The Rearvue doesn’t just see an amorphous blob approaching, it analyzes the size and movement of the vehicle and categorizes threats as Small, Medium, or Large.
When you look down at your Edge unit, you won’t just see a dot to symbolize an approaching vehicle. Instead, you’ll know if it’s a friendly Fiat X1/9 (Small) or a Ford F-350 that thinks the white line is a suggestion (Large).
Garmin has also introduced Threat Level detection, which analyzes the speed and path of the car. Not sure what you do with that information, exactly, beyond holding your breath and praying, but more data is always good. Even data about your possible imminent demise.
Brake Lights for your Bike
The RearVue 820 also functions as a legitimate smart brake light. Using its internal accelerometers, it detects when you are slowing down or stopping and changes its flash pattern to alert the person behind you.
We reviewed a different light that did this, and it didn’t work amazingly well. Or it was hard to assess how well it worked. That was six years ago though, and it wasn’t made by Garmin. Both factors mean this iteration of the concept probably actually works by now. We’ll confirm, if Garmin ever sends us a loaner device for testing (the last time they sent us something was 2010, so don’t wait up too late for us to update this section).
Specs for the Nerds
- Battery Life: Up to 24 hours in day flash and 30 hours in radar-only mode
- Range: It detects vehicles from 190 yards away
- Same Speed Tracking: It now notices cars that are “hovering” behind you at your speed, waiting to pass
- Charging: USB-C
The Verdict
The Varia has long since become an essential piece of kit. This new version, from first glance, pushes it to the next level with improvements and feature introductions across the board. We haven’t seen it in real life, but if it makes you safer on the bike, or even just gives you a cool brake light gizmo, then it’s worth every penny.